This invention relates to a functionalized oligomeric lubricant additive which imparts both enhanced anti-oxidancy and corrosion resistance upon dissolution in lubricating oils.
More specifically, this invention relates to railway diesel lubricants and, more particular, to diesel fuels containing anti-corrosion and anti-oxidation additives for improving the corrosion inhibition and anti-oxidation properties in motor fuels.
The price of diesel fuel has increased dramatically over the past 10 years. For example, the price of marine diesel fuel has increased from $11 a metric ton to a high of about $200 a metric ton. Additionally, a similar increase in fuel cost has been experienced by the railroad industry. These price increases have resulted in the cost of fuel being the largest expense for the owners of any diesel fleet of vehicles. To try to obtain some relief from this large expense, the railroads have embarked on a program of mixing poorer grade fuels (such as marine residual) with regular D-2 diesel fuel. While they do realize a savings from this mixed fuel operation, performance problems arise, such as increased corrosion and poorer oxidative stability. The magnitude of the problem can be gauged by General Electric's spending $20 million dollars to build new test facilities to evaluate these parameters. General Motor is also exerting a similar type of effort.
The present invention deals with the scenario where diesel fuel (D-2) is extended with diesel residual fuel. More specifically, we have simulated the scenario wherein Railway Diesel Oil (RDO) is contaminated with a given amount of marine diesel residual fuel. We believe this to be a realistic test since during the normal engine operation D-2 gets into the diesel crankcase. Finally, the Union Pacific Oxidation Test (UPOT) was used to evaluate the effectiveness of the experimental additives in reducing corrosion and oxidative thickening of the RDO.